The present invention relates to a method and a device for carrying out operations and/or manipulations in a well drilled into oil-bearing or gas-bearing geological formations, in particular a horizontal well.
The invention applies in particular to exploitation in stages of geological formations, and permits the flowrate, temperature, pressure, etc. measurements that may be made on the effluents from each producing formation.
For this type of application, the invention is particularly advantageous because of the speed of implementation of the device and method according to the invention, since it does not exclude certain types of work, such as those using the so-called wire line technique, that one may be called upon to use during production.
The invention also allows downhole tools to be controlled, which tools may be, for example, valves controlling selective production from a geological formation.
The controls of the tools or measurements with the method or device according to the invention are particularly advantageous because of the speed of their implementation (via the inside of the casing) and the full opportunities for manipulating the casing (rotation, advance, disassembly, etc.) which are unhampered by fixed or peripheral lines such as those currently used.
The invention applies advantageously to production by horizontal wells. Particularly in oil drilling, production by a well causes displacement of the various layers of liquids in the producing zone, a phenomenon called coning. In production in horizontal wells, undesirable fluids such as water generally arrive irregularly along the well so that a large portion of the liquid sought, such as oil, is not extracted from the formations.
There are two approaches to overcoming this drawback, for example, several producing zones are created and equipped with means such as valves that allow the flowrate to be controlled; and the quality and quantity of the fluids coming from each of the producing zones are controlled. This control may be effected by instruments such as flowmeters and physical and/or chemical instruments for measuring fluids, disposed, for example, along the well or casing according to each of the producing zones.
The invention furnishes a method for carrying out operations and/or manipulations such as measurements in a well having a casing with a smaller diameter than that of the well, with the well being drilled into geological formations and having at least two distinct producing zones.
In accordance, with the method of the present invention, each of the two zones of the well is equipped with at least one instrument and/or tool designed to perform the operations and/or manipulations, and the casing is equipped with a first connector usable in a liquid medium. The instruments and/or tools are connected to the first connector by lines, with a transmission cable, equipped with a sucking connector designed to connect to the first connector, being introduced into the casing. The second connector is moved until it cooperates with the first connector, and the operations and/or manipulations are carried out by controlling the tools and/or instruments by the transmissions cable.
The tools and/or instruments may, in accordance with the present invention, may be integral with the casing, and the distinct zones may be fluid-producing zones.
At least one of the instruments may be designed to measure the physical and/or chemical and/or physicochemical characteristics of the fluids present in a producing zone. At least one of the tools may be designed to modify fluids in the producing zone.
The first connector may be disposed at the lower end of the casing.
When the zones are producing zones, the fluids produced by these producing zones may be transferred inside the casing, and the casing may be equipped with means for allowing selective production from the well.
When the first connector is disposed at the lower end of the casing, a pipe designed to communicate with the lower end of the casing by a hydraulic connector and/or a passageway may be disposed at the lower end of the casing, this connector and this passageway being located above and/or below the level of the first connector.
The invention also provides a device for conducting operations and/or manipulations such as measurements in a well having a casing, with the casing having a smaller diameter than a diameter of the well being drilled into geological formations and having at least two distinct zones. The device also has in its interior a first connector usable in a liquid medium, with the first connector being connected by lines to at least one instrument and/or tool disposed in each of the zones. The first connector is designed to cooperate with a second connector connected by a transmission cable to the surface of the ground with the casing being designed to allow the second connector to be lowered from the surface and connected with the first connector.
When the zones are fluid-producing zones, the casing may hold the tools and/or instruments.
When the zones are fluid-producing zones and the casing has means allowing these zones to communicate with the inside of the casing, these means may allow selective production from the well.
The first connector may be disposed at the lower end of the casing.
The device may include a pipe communicating with the casing essentially at the level of the first connector and terminating at the surface of the ground.